Thanks for the link Dottie. It's interesting how they change the weights of different categories based on the census.
My tester actually sent me that today.
She was surprised that while the norming sample had a decrease of -1 to -5 on various subtests from th 5 years old age group, my son had some that were -30. She plans to add some of the statistical stuff to the report.
The thing is that -5 is an average difference. -5 is actually a huge % difference if applied to score of 100. Going from 100 to 95 means going from 50% to 36.9%. The changes around 100 are probably smaller, I just wanted to show the difference.
When you start looking at the other end of the curve, 5 points won't take you too far. 182 to 177 is 99.9999977% to 99.999986% that's a negligible difference not to mention that it cannot be measured anyway. It's not that surprising that the difference is much higher there.
Even though the jump from 182 to 157 sounds enormous but the difference is in 0.001 (from 99.99999 to 99.99276). Nobody can measure even that. Normal distribution is a nice model and it works really well for huge majority of the people, but it falls apart on both ends of the curve simply because the testing samples can be only that big.
Earlier quote:
While there are less subtests at the lower ages, they are also much "easier" to score extremely high on. For example, early readers can hit scores over 200 on the WJ for some very basic skills! This is also true for the math. In that regard, you probably won't have a great picture until your child is more "school aged", but you can get one that does tell you your child is indeed statistically rare.
Looking at score changes in crisc's son's test, I would think that 200 scores will be quite rare now. When you see one, it may be worth asking when the test was performed and if the updated tables were used. On the other hand I could see how it was possible to get close to 200 with the old norms at the age 3 to 5. Looking at the changes my guess would be that 3-4 got hit even harder than 5.
